An insulating, filling or packing material is known from DE 197 57 418 B4. It contains leaf mass made of Typha, the aerenchyma of which is largely preserved. The leaves are cut in the longitudinal direction. It is indicated that leaf segments having a maximum length of 15 cm, preferably 2 to 6 cm, are used. The particles are compressed under high pressure of more than 1 bar after adding an adhesive.
In one embodiment of DE 197 57 418 B4, the lower thirds of the bulrush leaf mass, glued with Sorel cement adhesive, are inserted parallel as leaf bundles with a length of 60 cm in a U-shaped frame. This generates a packet that is 2 m wide, 1.20 m high and 60 cm deep. Then the leaves are compressed and bonded in the process. The compression is so moderate that essentially only the interstices between the leaves disappear, while the aerenchyma volume is not significantly reduced. Then the packet is cured. Thereafter, panels having a thickness of approximately 7 cm are cut out perpendicularly to the leaf axes. Thus panels are obtained in which the leaves extend along the thickness of the panels. These panels serve as the core layer for sandwich elements, which must comprise cover layers. The cover layers are obtained from the upper third of Typha leaf plants. For this purpose, longitudinal strips approximately 2.5 mm wide are cut, from which pieces approximately 10 cm long are then cut. The mixture of leaf strips is discharged by a spiked roller as a nonwoven fabric about 4 cm high, pre-dried with hot air and then pressed into plates having a thickness of about 3 mm.
From EP 2 295 659 A2, a heat-insulating element based on Typha leaf mass is known. The particles are drastically comminuted in mills, so that particles measuring from tenths of millimeters to several millimeters are generated. In this way, the leaf structure is destroyed before the material is mixed with binding agents and pressed into bodies. The described heat-insulating elements have good insulating properties and are dimensionally stable, but have no significant load-bearing capacity.